Latch mechanism for explosively actuated tool



Nov. 24, 1959 w. J. CRANSTON 2,913,728

LATCH MECHANISM FOR EXPLOSIVELY ACTUATED TOOL Filed Dec. 9. 1957 I2FlG.l I0 46 44 56 20 IN VEN TOR. 38

\ WILBER ILCRANSTON BUC KHORN, CHEATHAM &BLO RE ATTORNEYS nited StatesLATCH MECHANISM FOR EXPLOSIVELY ACTUATED TOOL Wilber J.-Cranston,Milwaukie, reg., assignor to Omark Industries, Inc., Portland, Greg acorporation of Oregon Application December9, '1957, Serial No. 701,635 7Claims. (Cl. '1-44.S)

This invention relates to a latch mechanism for anexplosivelyactuated'tool and more particularly to a latch mechanism/fora tool of the type in which a handle portion is pivotally'connected toa'barrel portion so that the two portions of the tool may be pivotedwith respect to each other between an open condition of the tool and aclosed condition, theimproved latch mechanism of the presentinvention'reducing wear and damage to the engaging'portions of thelatch.

In severaltypes of commercial explosively actuated tools, the handleportion of the tool is pivotally secured to the barrel portion thereofin order to enable such portionso'f the tool-to bepivoted relativeto'each other from a closed condition-of the "tool in which the tool maybe fired to an" open conditionin which the tool may be loaded and thenback to a closed condition. In certain types of such tools, the tool islatched in closed condition by latch elements engaged by a forwardmovement of the handle portion of the tool relative to the barrelportion as the two portions-ofthe tool approach closed condition of thetoo'l. 'The forward motion of the handle portion relative to the barrelportion is produced by a spring urgingthe twoportions of the toolstoward each other and during'the finalelosing movement of the tool, thelatch elements are in=contact with each other during relativelateral-movement'o'f such latch elements and such elements are "subject"to "substantial wear when the tool is repeatedly opened'and closedbyworkmen using'the tool. Also,-the engaging portions of the'latchmechanism-are subjected to impact when theto'ol is rapidly closed. Inthe particular tool disclosed in the present application,-one ofthelatch engaging elements is a relatively thinrearwar'dly extendingmernb'erwhich may be bent by such impacts so that the latch nolongerfunctions.

In accordance with -the present-invention, the latch elements are heldout of contact with each other until the two portions of the tool arebrought into axial alignment during-closing of the tool. Thus a memberslidable in the barrel portion of thetoolis held in a rearward positionto which it is moved during opening of the tool. *Upon such rearwardmovement of the slidable member,-a plung'er carried by-isu'ch member isspring pressed outwardly to engage the housing of the barrel portion ofthe tool :so :aslto prevent:forward motion of such member ;until= theplungersis depressed inwardly into the :slidalble menrber. Sueh plunger:is depressed inwardly by :an element carried by the handle portion ofthe tool so 'that the rplnn'gerfis'zmoved. out of engagementwith thehousingo'f 'the barrelzportion ofthetool only when the handleiporti'on'reaches'ta'lignment with the barrel portion of *thel'tool. This releasesthe member slidable in the barrel portionbfsthe tool 'sothatit can becarried forwarldly 'byr the :spring referred to to carry the latchelementsdntoengagement with each other. Such forward movement cannot, howeverybe. produced until the handle portion'of'the tool-is in axialalignment with the'barrel portion. This .prevents engagement between thelatchingelements untilthe'pivota'l movementbetween the two atentZ,9l3,728 Patented Nov. 24, 1959 2 ice portions'of the tool to theclosed condition of the tool has been completed. The result is theprevention of wear of the engaging surfaces of the latch elements andthe prevention of bending of a latch element out of operative position.

It-is therefore an object of the present invention to provide animproved latch mechanism for holding in closed condition an explosivelyactuated tool having the barrel portion and handle portion thereofpivotally connected to each other to provide for moving such portionsrelative to each other from an open condition of the tool :to a closedcondition of the tool.

Another object of the invention is to provide an improveddatch mechanismfor-an explosively actuated tool having a handle portion pivotallyconnected to a barrel portion in which the contacting portions of thelatch mecha'nism are maintained out'of engagement during relative-pivotal motion of such handle and barrel portions of the=toolduring-closing of the tool until the handle portion ha's been broughtinto axial alignment with the barrel portion.

-A still further object of the invention is to provide a latch mechanismfor an explosively actuated tool having a barrel portion and a handleportion pivotally secured to each other to provide for opening andclosing the tool and movable longitudinally with respect to each otherbetween a latch engaging and a latch disengaging position in whichthelatch elements are maintained out of c'ontact until the two portions ofthe tool reach axial alignment with each other during a tool closingoperation in order to preventdamage to latch elements.

Other -objects and advantages of the invention will appear .in thefollowing description of a preferred embodim'ents'hown in the attacheddrawings of which:

Fig. 1 is a side elevation of a tool in accordance with the ;presentinvention with parts broken away to show the engagingportions of thelatch elements;

.Fig. 2is a plan view of the tool with portions broken away to showinternal structure;

Fig. 3 is a side elevation of the tool showing the oppositeside fromthat shown in Fig. 1 with the barrel and breech'block and the pivottherebetween shown in dotted lines;

JFig.:4 is a fragmentary plan view 'of the tool with the muzzle. of thetool oriented in the same direction as in Fig. 3 and with parts brokenaway to show the latch structure; and

Fig. 5is a view similar to Fig. 4 with the handle portion of the toolpartially pivoted with respect to the barrel portion toward the openedcondition of the tool.

Referring more particularly to the drawings, the tool shown therein hasa barrel portion 10 and a handle portion 12. The barrel portion 10includes a rubber covered barrel housing sleeve 16 and a barrel blocksleeve 20, which to'gether form a barrel housing. The barrel blocksleeve 20'has a ring portion 22 at its front end surrounding and'suitably'secured to the rear end of the barrel housing sleeve 16'andalso has rearwardly extending side portion 24 on-one side thereof,forming one latch element of the latch mechanism as described in moredetail below. The barrel block sleeve also has a shorter rearwardlyextending 'side'portion 26 on its other side which forms part sleeve 20,as indicated in Figs. 4 and 5. The barrel block 30 'is urged toward thefront or muzzle end of the tool by a compression spring 32 (Figs. 2 andsurrounding the barrel 28 and having its rearward end engaging againstan inwardly directed flange 34 on the barrel housing sleeve 16 and itsforward end engaging the rearward end of a the rear end of the barrelhousing sleeve 16.

The handle portion 12 of the tool includes a breech block 38, the rearportion of which is shown in Figs. 4 and 5 in horizontal section. Suchbreech block 38 is in the form of a U-shaped yoke, as indicated by thedotted lines in Fig. 3, and has forwardly extending leg portions aboveand below the barrel block 30 and in contact there- As shown in Fig. 4,the rearwardly extending latch elev tioned portion providing the otherlatch element of the tool. In the position of the parts shown in Fig. 4,the

two latch portions 54 and 56 interlock so as to prevent pivoting or thehandle portion 12 of the tool toward an open pos1t1on of the tool aboutthe pivot pin 42. By

extending bore 62 m the barrel block 30 and, as shown in Fig. 4, 1s heldin depressed position against the action of the spring 64 by both therearwardly extending side portion 26 of the barrel block sleeve 20 and aportion 66 of the action housing sleeve 44. That is to say, the actionhousing sleeve 44 is notched to fit around the rearwardly extending sideportion 26 of the barrel block sleeve and it is the portion 66 of theaction housing sleeve which is adjacent the rearward end of the sideportion 26 of the barrel housing sleeve 20 which also holds the plunger60 in the position shown in Fig. 4. When the handle portion 12 of thetool is moved rearwardly with respect to the barrel block sleeve 20 andthen pivoted toward the position shown in Fig. 5 soas to be movedfurther rearwardly by the camming action of the corner 58 of the breechblock 38 engaging the rear surface of the barrel housing sleeve 16, theplunger 60 clears the rearward end of the side portion 26 of the barrelblock sleeve and is moved outwardly to the position shown in Fig. 5 bythe spring 64. The plunger 60 is held against further movement outwardby a pin 68 carried in the barrel block 30 and engaging in a recess 70'in one side of the plunger. The other side of the plunger also has arecess for clearing the end of the cartridge removing member 52.Engagement of the plunger 60 behind the end of the side portion 26 ofthe barrel block sleeve 20 holds the barrel block 30 rearwardly withrespect to the barrel block sleeve and in the position shown in Fig. 5.The handle portion 12 may then be pivoted further to fully open positionof the tool or may be pivoted back toward closed position of the toolwhile the barrel block 30 is held in its rearward position.

When the handle portion 12 is pivoted toward the closed tool conditionshown in Fig. 4, the latch portion 56 of the action housing sleeve 44clears the barrel block, as shown by the dotted'line 72, and also clearsthe latch portion 54 0f the latch element 24 of the barrel block sleeve20. The portion 66 of the action housing sleeve 44 comes into contactwith the plunger 60 as the handle portion 12 of the tool approachesaxial alignment with the barrel portion 10 and as it comes intoalignment, the plunger 60 is depressed sufiicient that it clears the endof the side portion 26 of the barrel block sleeve 20, such that thespring 32 may return the barrel block 30 forwardly of the tool and intocontact with the rear end of the barrel housing sleeve 16. This movesthe latch portion 56 of the action housing sleeve 44 into engagementwith the latch portion 54 of the barrel block sleeve 20 to latch thetool in closed condition. It will be noted, however, that there is nocontact between the latch portions of the handle portion of the gun andthe barrel portion of the gun until the handle and barrel portions arein axial alignment. Thus there is no tendency to bend the rearwardlyextending side portion or latch element 24 of the barrel block sleeveout of latch engaging position. Also wearing of the latching portions ofthe two pertions of the gun because of relative lateral motion of suchparts when in engagement with each other is eliminated.

The operation of the latch mechanism of the present invention should beapparent from the above description. When the tool is in the tool closedcondition shown in Figs. 1 to 4, inclusive, it can be employed to fire astud into a work suface as is well known in the art. The handle portionof the tool may then be pivoted to the tool opened position of Fig. 4 bypulling the handle member 46 rearwardly with respect to the barrelhousing sleeve 16 and barrel block sleeve 20 to release the latchingportion 56 of the action housing sleeve 44 from the latching portion 54of the barrel block sleeve 20. This carries the barrel block 30rearwardly with respect to the barrel housing sleeve 16 against theforce of the spring'32. The pull exerted on the handle portion 46 withrespect to the barrel housing sleeve will ordinarily carry the barrelblock 30 sufiiciently rearwardly withrespect to the barrel block sleeve20'that the plunger 60 will snap out of its depressed position, shown inFig. 4, behind the end of the side portion 26 of the barrel blockhousing as soon as the handle portion. of the tool is pivoted towardtool opened position. In any event, when the handleportion hasbeenpulled sufliciently rearwardly to cause the latching portion 56 ofthe action housing sleeve 44 to clear the latching portion 54 of thebarrel block sleeve 20, the handle portion 12 of the gun may be pivotedto the position shown in Fig. and the camming action .of the corner 58of the yoke leg portions 40 of'the breech block 38 against the rearsurface of thebarrel housing sleeve 16 will move the barrel block 30.sutficiently rearwardly to cause the plunger 60 to clear the end of theside portion 26 of the barrel block sleeve 20. Such plunger thus assumesthe position shown in Fig. 5 and the continued pivoting of the handleportion.12 of the tool will cause the corners 58 of the yoke portions 40of the breech block to disengage the rear surface of the barrel housingsleeve 16. The barrel block 30 will, however, be maintained in itsrearward position-by the plunger 60 engaged against the rear end of theside portion 26 of the barrel block sleeve.

With the tool in its complete open position, a spent cartridge in thebreech plug 48may be removed therefrom by removing the breech plug fromthe end of the barrel 28 and sliding it onto the cartridge removingmember 52. A stud may then be inserted into the barrel through thebreech end thereof and the breech plug 48 may then be replaced in thebarrel. A blank cartridge may then be inserted into the breech blockafter which the tool may be closed by pivoting the handle portion 12about the pivot pin 42 with respect to the barrel portion toward theclosed tool position shown in Fig. 4. The latch portion 56 of the actionhousing 44 clears the end of the barrel block 30 and the latchingportion 54 of the barrel block sleeve and as the handle portion 12approaches axial alignment with the barrel portion 10, the portion 66 ofthe action housing .sleeve 44 engages the end of the plunger 60 todepress theasame. The plunger becomes fully depressed when the twoportions of the tool reach axial alignment and this allows the barrelblock 30 to be moved forwardly by the spring 32 to carry the breechblock 38 forward along with the action housing sleeve 44, thus causingthe latch .portion56 thereof to engage the latch portion 54 of thebarrel sleeve 20. Such engagement is by an axial reciprocation motiononly, thus avoiding any contact betweenthe latching portions of the twosleeves during relative lateral motion thereof. As explained above, thisprevents the bending of the latching portions and undue wear thereon.

While'I have disclosed a preferred embodiment of my invention, it isunderstood that the details thereof may be varied and that the scope ofthe invention is to be determined by the following claims.

I claim:

1. In an explosively actuated tool having a barrel portion, a handleportion movable longitudinally of said barrel portion, resilient meansurging said handle portion forwardly relative to said barrel portion,said handle portion being pivoted to said barrel portion to provide forpivotally moving said portions relative to each other between a closedcondition of said tool in which said portions are in axial alignmentwith each other and an opened condition exposing the rear end of saidbarrel portion, a latch mechanism for holding said tool in said closedcondition comprising latch elements on said portions engaged by forwardmovement of said handle portion relative to said barrel portion by saidresilient means when said tool is in closed position and releasable bymoving said handle portion rearwardly of said barrel portion against theforce of said resilient means, and means rendered operative by relativepivotal movement of said portions from said closed condition toward saidopened condition for holding said handle portion in a predeterminedrearward position preventing engagement of said latch elements untilsaid portions are pivotally moved into axial alignment with each other.

2. In an explosively actuated tool having a barrel portion including amember movable longitudinally of :said barrel -portion,- resilientmeansurging said member toward the forward end .of said barrel portion and ahandle portion pivoted to said member to .provide for pivotally movingsaid portions relative to .each .other .between a closed condition ofsaid tool in which said portions are in axial alignment with each otherand an opened condition exposing the rear end of said barrel portion,alatch mechanism for holding said tool 'in said closed conditioncomprising latch elementson said vportions engaged by forward movementof saidhandle portion relative to said barrel portion by said resilientmeans whensaid tool is in closed position and releasable by moving saidhandle portion and said member rearwardly of said barrel portion againstthe force of said resilient means, andmeans rendered operative byrelative pivotal movement of said portions from said closed conditiontoward ,said opened condition for holding said 'handle portion in apredetermined rearward position relative to vsaid barrel portion toprevent engagement of said latch elements until said portions arepivotally moved into axial alignment with each other.

3. In an explosively actuated toolhaving a barrel portion including abarrel, a barrel housing, a member movable longitudinally of said barrelhousing, resilient means urging said member toward the forward end ofsaid barrel housing and a handle portion pivoted to said member toprovide for pivotally moving :said portions relative to each otherbetween a closed condition of said tool in which said portions are inaxial alignment with each other and an opened condition exposing therear end of said barrel, said handle portion including an actionhousing, a latch mechanism for holding said tool in said closedcondition comprising latch elements on said housings engaged by forwardmovement of said handle portion relative to said barrel portion by saidresilient means when said tool is in closed position and releasable bymoving said handle portion and said member rearwardly of said housingagainst the force of said resilient means, and holding means renderedoperative by relative pivotal movement of said'portions from said closedcondition toward said opened condition for holding said member inapredetermined rearward position relative to said barrel portion toprevent engagement of said latch elements until said portions arepivotally moved into axial alignment with each other, said handleportion having a part engaging said holding means to release saidholding means when said portions are moved into said axial alignment.

4. In an explosively actuated tool having a barrel portion including abarrel, a barrel housing and a first mem ber movable longitudinally ofsaid barrel portion and resiliently urged toward the front end of saidbarrel housing and a handle portion including a second member pivoted tosaid first member for pivotal movement about an axis extending at rightangles to said barrel to provide for pivotally moving said portionsrelative to each other between a closed condition of said tool in whichsaid portions are in axial alignment with each other and an openedcondition exposing the rear end of said barrel, a latch element carriedby said handle portion and engaging said housing to hold said tool inclosed position when said first member is in a forward position relativeto said housing and releasable by moving said handle portion and saidmembers rearwardly of said housing and means rendered operative byrelative pivotal movement of said portions from said closed conditiontoward said opened condition for holding said first member in apredetermined rearward position relative to said housing to preventengagement of said latch elements until said portions are pivotallymoved into alignment with each other.

5. In an explosively actuated tool having a barrel por tion including abarrel, a barrel housing and a first member movable longitudinally ofsaid barrel portion and resiliently urged toward the front end of saidbarrel housing and a handle portion including an action housing andsecond member pivoted to said first member for pivotal movement about anaxis extending at right angles to said barrel toprovide forpivotally'moving said portions relative to each other between a closedcondition of said tool in which said portions are in axial alignmentwith each other and an opened condition exposing the rear end of saidbarrel, a latch element carried by said action housing and engaging alatch element on said barrel housing when said first member is in aforward position relative to said barrel housing to hold said tool inclosed position and releasable by moving said handle portion and saidmembers rearwardly of said barrel housing and holding means renderedoperative by relative pivotal movement of said portions from said closedcondition toward said opened condition for holding said first member ina predetermined rearward position relative to said barrel housing toprevent engagement of said latch elements until said portions arepivotally moved into alignment with each other, said action housinghaving a part engaging said holding means to release said holding meanswhen said portions are moved into axial alignment.

6. In an explosively actuated tool having a barrel portion including abarrel, a barrel housing and a member movable longitudinally of saidbarrel portion and re siliently urged toward thefront end of said barrelhousing and a handle portion including a second member pivoted to saidfirst member for pivotal movement about an axis extending at rightangles to said barrel to provide for pivotally moving said portionsrelative to each other between a closed condition of said tool in whichsaid portions are in axial alignment with each other and an openedcondition exposing the rear end of said barrel, a latch mechanismcomprising latch elements on said portions engaged with each other byforward movement of said handle portion relative to said housing whensaid tool is in closed position and releasable by moving said handleportion and said first member rearwardly of said housing, a holdingmember carried by said first member and movable outwardly thereof toengage said housing to hold said first member in a predeterminedrearward position relative to said housing when said first member 7barrel housing, a plunger carried is moved rearwardly of said housingand said portions are pivotally moved relative to each other from saidclosed condition toward said opened condition, said handle portionhaving a part engaging said holding member to move it out or engagementwith said housing when said portions are piv'oted toward closed positionand brought into axial alignment with each other so that engagement ofsaid latch elements is prevented until said portions are in axialalignment and engagement of said elements is by relative movementaxially of said tool.

7. In an explosively actuated tool having a barrel portion including abarrel, a barrel housing and a member movable longitudinally of saidbarrel portion and resiliently urged toward the front end of said barrelhousing and a handle portion including an action housing and a secondmember secured in said action housing and pivoted to said first memberfor pivotal movement about an axis extending at right angles to saidbarrel to provide for pivotally moving said pontions relative to eachother between a closed condition of said tool in which said portions arein axial alignment with each other and an opened condition exposing therear end of said barrel, a latch mechanism comprising latch elementscarried by said housings and engaged by forward movement of said handleportion relative to said barrel housing when said tool is in closedposition and releasable by moving said handle portion and said firstmember rearwardly of said by said first member and movable outwardlythereof to engage said barrel housing to hold said first member in apredetermined rearward position relative to said barrel housing whensaid first member is moved rearwardly of said barrel housing and saidportions are pivotally moved relative to each other from said closedcondition toward said opened condition, said action housing having apart engaging said plunger to move it out of engagement with said barrelhousing when said portions are pivoted toward closed position andbrought into axial alignment with each other so that engagement of saidlatch elements is prevented until said portions are in axial alignmentand engagement of said elements is by relative motion axially of saidtool.

No references cited.

